#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
int main(void)
{
    int testdev;
    int i, rf = 0;
    char buf[15];
    memset(buf, 0, sizeof(buf));
    testdev = open("/dev/chardev0", O_RDWR);
    if (testdev == -1)
    {
        perror("open\n");
        exit(0);
    }
    rf = read(testdev, buf, 12);
    if (rf < 0)
        perror("read error\n");
    printf("R:%s\n", buf);
    close(testdev);
    return 0;
}